Thermal erosion behavior of electroplating and multi-arc ion plating Cr coatings on PCrNi3MoVA steel

Abstract The thermal erosion behavior of two-kind Cr coating on PCrNi3MoVA steel under 350 MPa erosive pressure is compared. Microscopic observations and elemental analyses of the two-kind Cr coatings are carried out by scanning electron microscopy (SEM) and energy dispersion spectrometer (EDS), which led to their exfoliation mechanism. It is found the spalling mechanism of the two-kind Cr coatings after thermal erosion is different: the spalling of the electroplating Cr coating is in the form of localized delamination to overall spalling over a large area, and the spalling of the multi-arc ion plating Cr coating is in the form of horizontal and vertical extended spalling. The results show that the electroplated Cr coating has weaker erosion resistance than the multi-arc ion plating Cr coating and the Cr coating by multi-arc ion plating is more suitable as a protective layer to extend the life of the gun barrel.